STARDUST Launch Sequence Description

The Boeing Delta II 7426 launch vehicle consists of three stages
stacked on top of each other, plus 4 small solid-fuel rockets strapped to
the outside of the first stage. Each of the four solid rocket motors is
1 meter (3.28 feet) in diameter and 13 meters (42.6 feet) long; each contains
11,765 kilograms (25,937 pounds) of hydroxyl-terminated polybutadiene (HTPB)
propellant and provides an average thrust of 446,023 newtons (100,270 pounds)
at sea level. The casings on the solid rocket motors are made of lightweight
graphite epoxy.

At the very top of this "stack" is the spacecraft,
inside a protective metal shell.
Total weight of the
spacecraft,
including the sample return capsule and propellant carried onboard for
trajectory adjustments, is
385 kilograms (848 pounds). The main bus is 1.7 meters (5.6 feet) high, 0.66
meter (2.16 feet)
wide and 0.66 meter (2.16 feet) deep, about the size of an average office
desk.

Liftoff will take place from Space Launch Complex 17 at Cape Canaveral
Air Station, Florida. Each stage has its own rocket motor. The first two
stages use liquid rocket fuel. The third stage uses solid rocket fuel.

Launch occurs in three phases, consisting of liftoff and
insertion into a
189-kilometer (102-mile) parking orbit; a coast of about a half hour until
the vehicle position is
properly aligned relative to the direction it must leave Earth; and final
injection to an escape
trajectory. The total time needed to complete the process is a little under
an hour.

Sixty-six seconds after liftoff the 4 solid rocket "strap-ons"
are discarded and fall into the ocean. Two of the four solid rocket strap-ons
will be discarded first, and the remaining strap-on boosters will be jettisoned
one second later, while the first stage continues to burn. At this point,
the launch vehicle will be at an altitude of 21.9 km (13.5 miles) and traveling
at a velocity of 3,862 km/hour (2,390 miles/hour).

The central first stage continues to burn for about 3 minutes. The main
body of the first stage is 2.4 meters (8 feet) in diameter and 26.1 meters
(85.6 feet) long. It is powered by an RS-27A engine, which uses 96,160 kilograms
(212,000 pounds) of RP-1 (rocket propellant 1, a highly refined kerosene)
and liquid oxygen as its fuel and oxidizer.

4.4 minutes after liftoff the first stage shuts itself off (main engine
cutoff) and is discarded (first stage separation). The spacecraft is now
at an altitude of 114.5 km (71 miles) and traveling at a velocity of 20,096
km/hour (12,439 miles/hour). One stage down, two more to go!

13.5 seconds following main engine cutoff, the second stage is fired.
The second stage is 2.4 meters (8 feet) in diameter and 6 meters (19.7 feet)
long, and is powered by an AJ10-118K engine. The propellant is 5,900 kilograms
(13,000 pounds) of Aerozine 50 (A-50), a mixture of hydrazine and unsymmetrical
dimethyl hydrazine (UDMH), and nitrogen tetroxide as the oxidizer. This
engine is restartable, and will perform two separate burns during the launch.

The second-stage burn ends 11 minutes, 22 seconds after liftoff.
At this point, the vehicle will be in a low-Earth orbit at an altitude of
189 kilometers (117 miles). Depending on the actual launch date and time,
the vehicle will then coast for about 10 minutes. Once the vehicle is at
the correct point in its orbit, the second stage will be restarted for a
brief second burn.

Before the third stage's rocket is fired to get the spacecraft out of
Earth orbit and on its way, it has to be "spun up" first.
Small rockets are used to make the third stage spin about its long axis.
Actually, the third stage will spin on turntable attached to the second
stage.

The third and final stage of the Delta 7426 is a Thiokol Star 37 FM booster.
The
The spinning third stage separates from the second stage, and the the third
stage motor ignites, sending the vehicle out of earth orbit. The reason
we want the vehicle to spin during this burn is so it stays pointed where
we need it to point. Spinning it stabilizes it, like a spinning bullet fired
from a rifle. A nutation control system (a thruster on an arm mounted on
the side of the third stage) will be used to maintain stability during this
88-second burn.

STARDUST will then
separate from the Delta's third stage.
Immediately after separation from the Delta's third stage, Stardust will
stop its own
spinning by firing its thrusters.

About 4 minutes after separation, the
spacecraft's solar array
will be unfolded and be pointed toward the Sun. Shortly thereafter, the
34-meter-diameter
(112-foot) antenna at the Deep Space Network complex in Canberra, Australia
will acquire
Stardust's signal.